EP0261031A2 - Méthode et dispositif de correction d'erreur dans un système de traitement de données à processeur parallèle - Google Patents

Méthode et dispositif de correction d'erreur dans un système de traitement de données à processeur parallèle Download PDF

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Publication number
EP0261031A2
EP0261031A2 EP87402061A EP87402061A EP0261031A2 EP 0261031 A2 EP0261031 A2 EP 0261031A2 EP 87402061 A EP87402061 A EP 87402061A EP 87402061 A EP87402061 A EP 87402061A EP 0261031 A2 EP0261031 A2 EP 0261031A2
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EP
European Patent Office
Prior art keywords
data
memory
error
error correcting
processors
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP87402061A
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German (de)
English (en)
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EP0261031B1 (fr
EP0261031A3 (en
Inventor
W. Daniel Hillis
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Thinking Machines Corp
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Thinking Machines Corp
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Publication of EP0261031A3 publication Critical patent/EP0261031A3/en
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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/08—Error detection or correction by redundancy in data representation, e.g. by using checking codes
    • G06F11/10—Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
    • G06F11/1004—Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's to protect a block of data words, e.g. CRC or checksum
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/08—Error detection or correction by redundancy in data representation, e.g. by using checking codes
    • G06F11/10—Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F11/00—Error detection; Error correction; Monitoring
    • G06F11/07—Responding to the occurrence of a fault, e.g. fault tolerance
    • G06F11/08—Error detection or correction by redundancy in data representation, e.g. by using checking codes
    • G06F11/10—Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
    • G06F11/1008—Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's in individual solid state devices
    • G06F11/1048—Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's in individual solid state devices using arrangements adapted for a specific error detection or correction feature

Definitions

  • the present invention relates to a method and apparatus for error correction in the read/write cycles of plural memories in a parallel processor data processing system.
  • a simple form of error correction involves the use of a parity bit as an auxiliary digital bit in a multibit word which was either a binary one or a zero based upon a function of the bit characteristics of each bit position in a data word.
  • a difference, representing an error, between the digital word as read and the digital word as written into memory could be detected by the use of the parity bit in the case of a single, or odd number of bit errors in the word by recording the parity bit with the word as written to memory and comparing the retrieved parity bit with a reconstruction of the parity bit from the data word as read. If a difference occurred it was an indication of an error in an odd number of bits. Typically the probabilities of error were sufficiently low that the likelihood was insignificant of an error in all but a single bit. The use of the parity bit could not determine where the error existed but would alert the computer system to the presence of an error and auxiliary corrective steps, such as a second attempt to read data correctly could be utilized.
  • Error detecting circuitry is operative on the digital word and error correcting code read from memory to not only identify the existence of an error but to spot which bit might be in error and to provide a correction of it.
  • Error detecting circuitry is operative on the digital word and error correcting code read from memory to not only identify the existence of an error but to spot which bit might be in error and to provide a correction of it.
  • errors in one or more bit positions could be detected.
  • One common methodology utilized with a sixteen bit processor and memory uses a six bit error correcting code generated, as a function of each bit in a data word, by a specific algorithm that was adapted to provide recognition of the most common error types.
  • each memory associated with a single processor in such a parallel processor arrangement may be relatively small, for example on the order of 4K bits. While it is technically feasible to design a memory of that size which, by itself, would exhibit sufficiently low fault or error rates that no error correcting might be required, when considering that tens of thousands of such memories are typically employed in a parallel processor arrangement, the error likelihood increases dramatically as a statistical function of the entire assemblage of memories. As a result, it becomes necessary to apply error corrections to each of the thousands of such memories in a parallel processor arrangement. The cost of adding an error correcting system to each such memory greatly increases the costs of such a parallel processing system
  • a system for enhancing the effectiveness and efficiency of error correction in read/write operations of a plurality of memories associated with plural data processors in a parallel processor environment.
  • the reading and writing of data between a plurality of memories and associated parallel processor is synchronized and coordinated to form a single data word and a unitary error correction code determined from the single data word.
  • the single data word comprises a collection of data words to be written or read from plural memories.
  • the error correcting code developed taking the plural data words as a unitary word greatly enhances the efficiency and effectiveness of error correction in the multiprocessor environment.
  • the unitary error correcting code applicable to the single data word incorporating plural data words being read from and written to the plural memories can be a single parity bit or a more complex set of bits developed from one of several error correction algorithms designed to correct for error in one or more bit locations in the single, combination data word.
  • plural memories are typically coordinated by parallel processors of a computational facility in which the computational power is distributed into the plurality of parallel, and simultaneous acting small processors.
  • the memory, read/write data flow from or governed by a set of several of such processors is combined to form a single, simultaneously applied, data word which is stored in the plural associated memories along with an error correcting code developed by a unitary error correcting code generator forming the code as a function of the combined words from the plural processors.
  • the memory to which the combined word and associated error correcting code is applied may be plural separate memories, or segmented portions of a single hardware memory. Data read from such memory or memories is then processed by a unitary error detection and correction scheme to return a corrected combined data word which is then separated for application to or utilization by corresponding ones of the set of plural processors.
  • the present invention contemplates an enhancement in error correction capability in read/write functions associated with plural memories and corresponding processors, typically involved in a multiprocessor or parallel processor environment.
  • FIG.1 there is shown a block diagram representing the environment of a parallel processor system, and in particular such systems as are found in the above referenced incorporated applications.
  • a parallel processor environment will have a plurality of modules 12 representing small parallel acting processors and associated memories.
  • Such processors will typically be operated under the control of an external processor 14 through control lines 16, as is more fully described in the above referenced applications.
  • data flow between the processor and memory modules 12 within the parallel processor environment over data lines 18 is typically governed by a communication scheme whereby a set, N, of processor memory modules 12 may be in direct communication with each other whereas communication between other modules 12 would require data exchange through one or more other processors.
  • Additional control lines 20 are utilized to facilitate the flow of data and control signals throughout the multiprocessor environment as is more fully described in the above identified applications.
  • each processor memory modular 12 there exists an identifiable processor 24 and associated random access memory or memory 26.
  • Data communication may be directly between processor and memory or over a data bus 28 under the governance of a control interface 30 which determines read/write functions of data to the memory 26 in association with the processor 24.
  • Fig.2 illustrates a generalized relationship between processor and memory, neglecting input/output functions.
  • Fig.3 A generalized representation of such a scheme is illustrated in Fig.3.
  • the error correcting scheme corrects for the chance error that would cause a data word read from memory to differ in one or more bit positions from the data word recorded in memory.
  • data being applied to memory over a data bus 34 typically having a bit size, X, which in many cases is sixteen bits, is applied through latch or buffer circuitry 36 to the actual storage hardware of a random access memory 38.
  • Each data word on the bus 34 is also applied to an encoder circuit 40 which generates, according to a predetermined methodology, an error correcting code or data word having, typically, a shorter number of bits, Y, which is also applied through the interfacing circuits 36 to the memory 38 for storage along with the data word on the bus 34 at the same address.
  • the size of the error correcting code from the encoder 40 is typically six bits in length according to well known error correcting methodology.
  • the encoder 40 generates a code word which is a function of the specific bit states of the data word on the bus 34 and is statistically based to permit discovery and pinpointing of the most likely errors to occur in data read from the memory 38.
  • the error correcting code would be a duplicate of the originally recorded word.
  • the error correcting code would be a simple parity bit. In between there occurs a range of possibilities.
  • the statistical likelihood of error and its type determines the most advantageous and economical manner of generating a correcting code by the encoder 40. The object is to minimize the amount of additional circuitry and size of the error correcting code and memory space which must be allocated to it while at the same time providing a necessary level of reliability for accurate data writing and reading
  • the data from the bus 34 along with the error correcting code are applied through output buffers 42 respectively to an error correction circuit 44 and an error detecting circuit 46.
  • the error detector 46 determines by reading the error correcting code in association with the readout data whether or not an error has occurred. If an error has occurred, a decoder circuit 48 can determine, if that error is in one of the expected class of errors, where the error has occurred and instructs the error correction circuitry 44 to correct the readout data so that the data applied from the correction circuit 44 on an output bus 45 is an exact reproduction of the original word on the bus 34 applied to that memory address in the memory 38.
  • Fig.4 illustrates such a system in which a plurality of processors 50 and associated data buses 52, for application of data to be written to a memory, are associated such that the data on the buses 52 is assembled in an interface 54 into a single, large data word applied on an output bus 56.
  • the data in the bus 56 will have a byte size of "NX", where "X” is the original byte size of the data on the buses 52 and "N” represents the number of processors 50 associated with a single interface 54.
  • System timing and control circuitry 58 of the type typically provided in computer systems, is operated to ensure that all of the data from the buses 52 simultaneously appears on the bus 56 to form a single combination data word. This data word is applied through an interface or buffer system 60 to a memory 62.
  • the data on the bus 56 is applied to an error encoder 64 which generates an error code on a bus 66 for application through interface 60 to memory 62 for storage at the same address as the data on the bus 56.
  • the memory 62 may be plural separate memories or, as more typical, and as illustrated in Fig.5, may be a single memory 68 partitioned, in each address location into cells 70, one corresponding to each of the processors 50 and a final cell 72 containing the error correcting code on the bus 66. In this manner, the memory 62 can in fact be viewed as plural memories or plural memory areas each associated with one of the processors 50.
  • Data is read from the memory 62 from each address, including the plural cells 70 and error cell 72 on an output bus 74 through a buffer or interface 76 to an error correcting system 78.
  • the cell 72 is applied through a bus 74 through an interface 76 to an error detect and decode system 80 operative on the expanding error correcting codes generated for the larger data word on the bus 74 representing the combined data words associated with each processor 50.
  • the error correcting system 78 responds to an indication of error from the error detect and decoder system 80 to provide correction of the anticipated errors appearing in the combined data word on bus 74, applying a corrected data word on a bus 82 through an interface circuit 84 which distributes the combined word onto plural output buses 86, one each associated with one of the processors 50.
  • Data from each of the cells 70 for a single address is read simultaneously from the memory 62 to form a single large data word on which the error detecting system 80 can operate simultaneously to provide error correction as appropriate.

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  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Security & Cryptography (AREA)
  • Detection And Correction Of Errors (AREA)
  • Techniques For Improving Reliability Of Storages (AREA)
  • Multi Processors (AREA)
  • Debugging And Monitoring (AREA)
EP87402061A 1986-09-15 1987-09-15 Méthode et dispositif de correction d'erreur dans un système de traitement de données à processeur parallèle Expired - Lifetime EP0261031B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US907671 1986-09-15
US06/907,671 US4791641A (en) 1986-09-15 1986-09-15 Parallel processor error checking

Publications (3)

Publication Number Publication Date
EP0261031A2 true EP0261031A2 (fr) 1988-03-23
EP0261031A3 EP0261031A3 (en) 1989-11-02
EP0261031B1 EP0261031B1 (fr) 1994-06-01

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EP87402061A Expired - Lifetime EP0261031B1 (fr) 1986-09-15 1987-09-15 Méthode et dispositif de correction d'erreur dans un système de traitement de données à processeur parallèle

Country Status (7)

Country Link
US (1) US4791641A (fr)
EP (1) EP0261031B1 (fr)
JP (1) JP2738687B2 (fr)
AT (1) ATE106582T1 (fr)
AU (1) AU7820987A (fr)
CA (1) CA1292579C (fr)
DE (1) DE3789929T2 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993015460A2 (fr) * 1992-01-24 1993-08-05 Digital Equipment Corporation Circuit de parite et de normalisation haute vitesse des bus de donnees pour un systeme de traitement en parallele d'un grand nombre d'instructions
EP0800133A1 (fr) * 1992-01-24 1997-10-08 Digital Equipment Corporation Circuit de parité et de normalisation haute vitesse des bus de données pour un système de traitement en parallèle d'un grand nombre d'instructions

Families Citing this family (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3706734C1 (de) * 1987-03-02 1988-03-17 Force Computers Gmbh Verfahren zur UEbertragung von Daten sowie Computer
US5170482A (en) * 1987-08-14 1992-12-08 Regents Of The University Of Minnesota Improved hypercube topology for multiprocessor computer systems
EP0343742B1 (fr) * 1988-05-27 1995-08-09 Philips Electronics Uk Limited Décodeur de données codées selon le code Hamming
US5283791A (en) * 1988-08-02 1994-02-01 Cray Research Systems, Inc. Error recovery method and apparatus for high performance disk drives
US5218689A (en) * 1988-08-16 1993-06-08 Cray Research, Inc. Single disk emulation interface for an array of asynchronously operating disk drives
US5146461A (en) * 1989-11-13 1992-09-08 Solbourne Computer, Inc. Memory error correction system distributed on a high performance multiprocessor bus and method therefor
US5170370A (en) * 1989-11-17 1992-12-08 Cray Research, Inc. Vector bit-matrix multiply functional unit
US5280474A (en) * 1990-01-05 1994-01-18 Maspar Computer Corporation Scalable processor to processor and processor-to-I/O interconnection network and method for parallel processing arrays
WO1991010200A1 (fr) * 1990-01-05 1991-07-11 Maspar Computer Corporation Systeme de memoire avec processeurs en parallele
US5442797A (en) * 1991-12-04 1995-08-15 Casavant; Thomas L. Latency tolerant risc-based multiple processor with event driven locality managers resulting from variable tagging
US5524212A (en) * 1992-04-27 1996-06-04 University Of Washington Multiprocessor system with write generate method for updating cache
GB2268817B (en) * 1992-07-17 1996-05-01 Integrated Micro Products Ltd A fault-tolerant computer system
US5432801A (en) * 1993-07-23 1995-07-11 Commodore Electronics Limited Method and apparatus for performing multiple simultaneous error detection on data having unknown format
US5771247A (en) * 1994-10-03 1998-06-23 International Business Machines Corporation Low latency error reporting for high performance bus
US6356548B1 (en) 1998-06-29 2002-03-12 Cisco Technology, Inc. Pooled receive and transmit queues to access a shared bus in a multi-port switch asic
US6119215A (en) * 1998-06-29 2000-09-12 Cisco Technology, Inc. Synchronization and control system for an arrayed processing engine
US6513108B1 (en) 1998-06-29 2003-01-28 Cisco Technology, Inc. Programmable processing engine for efficiently processing transient data
US6101599A (en) * 1998-06-29 2000-08-08 Cisco Technology, Inc. System for context switching between processing elements in a pipeline of processing elements
US6195739B1 (en) 1998-06-29 2001-02-27 Cisco Technology, Inc. Method and apparatus for passing data among processor complex stages of a pipelined processing engine
US6836838B1 (en) 1998-06-29 2004-12-28 Cisco Technology, Inc. Architecture for a processor complex of an arrayed pipelined processing engine
US6728839B1 (en) 1998-10-28 2004-04-27 Cisco Technology, Inc. Attribute based memory pre-fetching technique
US6175941B1 (en) 1998-12-08 2001-01-16 Lsi Logic Corporation Error correction apparatus and associated method utilizing parellel processing
US6385747B1 (en) 1998-12-14 2002-05-07 Cisco Technology, Inc. Testing of replicated components of electronic device
US6173386B1 (en) 1998-12-14 2001-01-09 Cisco Technology, Inc. Parallel processor with debug capability
US6920562B1 (en) 1998-12-18 2005-07-19 Cisco Technology, Inc. Tightly coupled software protocol decode with hardware data encryption
US6529983B1 (en) 1999-11-03 2003-03-04 Cisco Technology, Inc. Group and virtual locking mechanism for inter processor synchronization
US6681341B1 (en) 1999-11-03 2004-01-20 Cisco Technology, Inc. Processor isolation method for integrated multi-processor systems
US6892237B1 (en) 2000-03-28 2005-05-10 Cisco Technology, Inc. Method and apparatus for high-speed parsing of network messages
US6505269B1 (en) 2000-05-16 2003-01-07 Cisco Technology, Inc. Dynamic addressing mapping to eliminate memory resource contention in a symmetric multiprocessor system
US7447872B2 (en) * 2002-05-30 2008-11-04 Cisco Technology, Inc. Inter-chip processor control plane communication
RU2513773C1 (ru) 2010-04-02 2014-04-20 3М Инновейтив Пропертиз Компани Фильтрующая система, включающая структурированные оптические датчики аналитов и оптические считывающие устройства
JP2020198044A (ja) * 2019-06-05 2020-12-10 富士通株式会社 並列処理装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4228496A (en) * 1976-09-07 1980-10-14 Tandem Computers Incorporated Multiprocessor system
US4255808A (en) * 1979-04-19 1981-03-10 Sperry Corporation Hard or soft cell failure differentiator
US4345328A (en) * 1980-06-30 1982-08-17 Sperry Corporation ECC Check bit generation using through checking parity bits
EP0075631A1 (fr) * 1980-06-03 1983-04-06 BURROUGHS CORPORATION (a Michigan corporation) Appareil d' enregistrement d'erreurs permanentes de lecture de mémoire
EP0141743A2 (fr) * 1983-11-07 1985-05-15 Digital Equipment Corporation Correction d'erreur à exécution pipe-line

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3660646A (en) * 1970-09-22 1972-05-02 Ibm Checking by pseudoduplication
US4215395A (en) * 1978-08-24 1980-07-29 Texas Instruments Incorporated Dual microprocessor intelligent programmable process control system
US4310879A (en) * 1979-03-08 1982-01-12 Pandeya Arun K Parallel processor having central processor memory extension
US4240156A (en) * 1979-03-29 1980-12-16 Doland George D Concatenated error correcting system
US4295218A (en) * 1979-06-25 1981-10-13 Regents Of The University Of California Error-correcting coding system
US4314350A (en) * 1979-12-31 1982-02-02 Bell Telephone Laboratories, Incorporated Self-checking arithmetic unit
JPS57100698A (en) * 1980-12-15 1982-06-22 Fujitsu Ltd Error correction system
US4414669A (en) * 1981-07-23 1983-11-08 General Electric Company Self-testing pipeline processors
US4473902A (en) * 1982-04-22 1984-09-25 Sperrt Corporation Error correcting code processing system
JPS5985153A (ja) * 1982-11-08 1984-05-17 Hitachi Ltd 冗長化制御装置
JPH0654505B2 (ja) * 1983-12-23 1994-07-20 株式会社日立製作所 並列型演算処理装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4228496A (en) * 1976-09-07 1980-10-14 Tandem Computers Incorporated Multiprocessor system
US4255808A (en) * 1979-04-19 1981-03-10 Sperry Corporation Hard or soft cell failure differentiator
EP0075631A1 (fr) * 1980-06-03 1983-04-06 BURROUGHS CORPORATION (a Michigan corporation) Appareil d' enregistrement d'erreurs permanentes de lecture de mémoire
US4345328A (en) * 1980-06-30 1982-08-17 Sperry Corporation ECC Check bit generation using through checking parity bits
EP0141743A2 (fr) * 1983-11-07 1985-05-15 Digital Equipment Corporation Correction d'erreur à exécution pipe-line

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
IBM TECHNICAL DISCLOSURE BULLETIN, vol. 14, no. 11, April 1972, pages 3380-3381, New York, US; R.G KIWIMAGI et al.: "Enhanced error correction" *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993015460A2 (fr) * 1992-01-24 1993-08-05 Digital Equipment Corporation Circuit de parite et de normalisation haute vitesse des bus de donnees pour un systeme de traitement en parallele d'un grand nombre d'instructions
WO1993015460A3 (fr) * 1992-01-24 1994-01-20 Digital Equipment Corp Circuit de parite et de normalisation haute vitesse des bus de donnees pour un systeme de traitement en parallele d'un grand nombre d'instructions
EP0800133A1 (fr) * 1992-01-24 1997-10-08 Digital Equipment Corporation Circuit de parité et de normalisation haute vitesse des bus de données pour un système de traitement en parallèle d'un grand nombre d'instructions

Also Published As

Publication number Publication date
JP2738687B2 (ja) 1998-04-08
CA1292579C (fr) 1991-11-26
DE3789929T2 (de) 1994-09-08
US4791641A (en) 1988-12-13
JPS6394353A (ja) 1988-04-25
EP0261031B1 (fr) 1994-06-01
ATE106582T1 (de) 1994-06-15
AU7820987A (en) 1988-03-17
EP0261031A3 (en) 1989-11-02
DE3789929D1 (de) 1994-07-07

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